In general and for context, a protected membrane roof (“PMR”) is generally a typically flat or minimally sloped roof having one or more layers of insulation (specifically extruded polystyrene) installed over the waterproofing membrane and deck assembly. This configuration provides for protection against UV radiation, thermal shock, the elements, and physical abuse for that vital waterproofing membrane below. It is noted that conventional low-sloped roofs place the membrane on top of the insulation, while in “PMR” roof assemblies, that waterproofing membrane is typically placed directly on the structural deck (except for metal decks where a substrate board is installed first). In order to provide “ballasting” for the insulation and “PMR” roof system in general, some type of ballast material such as stones, pavers, or soil (garden roofs) or the like is applied over the insulation layer(s) for further protection of the membrane as well as protection effects for wind uplift resistance for the underlying insulation boards. To protect against scour of the ballast material, it is often preferable to apply a netting over the ballast material (i.e., soil) and now to further expand that to other types of ballast such as pavers and stones. This netting which is applied over the ballast material, either at least around a swatch of the roof perimeter or over the entire roof, is then itself susceptible to wind uplift or being blown off the roof even if staked within the ballast material. To attempt to secure the netting against wind uplift, stakes or anchors are typically applied to or secured within the ballast material itself. On information and belief, the prior art anchoring approach, though perhaps relatively easily installed and relatively inexpensive, results in significantly reduced wind uplift resistance—on the order of only two to four pounds (2-4 lbs).
What is needed is a protected membrane roof system wherein a fastener assembly is secured beneath an insulation board thereof positioned beneath the ballast material for improved wind uplift resistance. Aspects of the present invention fulfill these needs and provide further related advantages as described in the following summary.